Testing machine



Jun 1 1924. MWMG .A. E. OXLEY TESTING MACHINE Filed Feb. 13 1924lllllllllllllllllllll flllllllllllllllllllll illllllflll! atented .lullyl, W24.

THUR ERNEST OXLEY, or DIDsBURY, NANcREsTER, ENGLAND, AssIeNoR To TBRITISH coTToN INDUSTRY RESEAIWH AssoorATIoN, or mnsRURY, Nome- TER, ENGAND.

TESTING MACHINE.

Application filed February 13, 1924. Serial No. 692,618.

Z all whom it may concern.

Be it known that- I, ARTHUR ERNEST Ox- LEY, a subject of the King ofGreat Britain, residing in Didsbury, Manchester; in the county. ofLancaster and Kingdom of England, have invented certain new and usefulImprovements in Testing Machines, of which the following is aspecification.

This invention relates to a machine for testing threads and the like.

According to'the present invention cyclical variation of stress isapplied to a length of thread suspended in a machine. Further by thisinvention means are provided to prevent the rotation of the thread aboutits axis to cause untwisting of the same.

This invention also includes a method. of recording automatically theextension of the thread in conjunction with the automatic recording ofthe number of cycles of the applied stress.

In one form of construction of the machine the threads are connected tocranks at one end and carry loadin weights at the other, the load beingsuch t at the maximum loading on the thread which occurs with the crankat one extreme position relatively to the thread will always be lessthan thebreaking load of the thread. The numbers of variation of stressapplied in this manner-previous to the rupture of the thread is ameasure of the strength of the thread when submitted to cyclical variations of stress. 4

scribed with reference to the accompanying drawings, in which;

Figure 1 shows a machine for mechanically causing a cyclical stress.

Figure 2 1s a detail View.

Figure 3 is a diagram of the'cut out circuit. I Figure 4 is a detail ofthe out.

Referring to Figs. 1 and 2 a device' for submitting threads to cyclicalvariations of stress is shown. Mounted on a suitable frame work 44 are aseries of bearings 45 in which is mounted a crank shaft 46 carryingcranks 47 the shaft 46 bein driven in any suitable manner as shown drive48. The cranks 47 are connected by a connecting rod 49 to slides 50working in guides 51 mounted on a suitable girder 52.

Attached to the slides 50 are screw grips electrical cut The inventionis more particularly dewith the lower edge of the cams by springs y thebelt I 53 supporting the threads 1, the lower end of which are attachedto lower grips 54 supporting weights 55 through a- ,bifilar suspension56 comprising a pair of cords passing through vertical lass or the liketubes 57 attached to a cross cam 58 by adjustable clamps 59. The bifilarsuspension prevents any untwisting action liable to occur in the thread.

Mounted below the member 58 is a catch board 60 clamped at any desireddistance to allow for a s ecimen of any desired length. The catch oard60 carries electrical contacts 61 arranged below the Wei hts 55 so thatif a specimen breaks its weig t falls upon the corresponding stud 61 tocomplete an electric circuit and thus to stop the ma' chine.

Arranged opposite the movement of the weights are graduated scales 64 sothat any extension of the thread may be recorded by reading the lowestposition of the weight at intervals. I Alternatively, the scales may bearranged opposite the point of attachment of the. thread to the bifilarmember 56, thus avoiding any possibility of the reading including anyextension of the bifilar members 56.

It is evident that as the cranks rotate the weights 55 are caused tomove vertically upwardsand downwards with a motion whichis-approximately simple harmonic and by their inertia produces acyclical variation of tension in the specimen 1.

Instead of the system of cranks and slides just described to roduce thesimple harmonic motion of t e weights, cams may be employed to give anydesired typeof motion, the connecting rods being held in contact orsupported by gravity from the upper edge. Alternatively the system ofcranks shown in Fig. 1 may be retained but the cranks driven at anon-uniform angular velocity by means of a cam driving mechanismoreccentric pulley. In this manner the motion given to each individualspecimen ma be varied to produce differences in the cyclical stress.

Figs. 3 and 4 show a convenient cut out mechanism.

Referring to Fig. 3 it will be seen that the motor M is connected acrossthe batte' A throu h the contact B and correspon ing mova 1e armaturecontact 0, so that on the 110 insertion of the switch the motor is suplied with current in the usual manner. (In the depression of the stud61 the relay circuit is complete causin the battery D to energize thecoils E of t e electro-magnet F in this manner pulling the contact arm 0and breaking the contact between B and C thereby stoppingthe motor.

Fig. 4 shows thestud 61 in detail which is maintained in an elevatedposition above the corresponding contact plates 62 by means of a s ring63.

I declaret at what I claim is 1. In a machine for testing threads or thelike the combination of means to. suspend said thread means to apply acyclical variation of tensile stress axially of said thread, and meansto prevent the rotation of said thread about its axis tending to untwistthe same.

2. In a machine for testing threads the combination of means to suspendsaid thread by one end thereof, a weight attached to the end of saidthread remote from said suspending means, means to move said suspendingmeans through a cyclical path to produce variation in the stressimparted to said thread, and means to prevent the untwisting of saidthread about its axis.

3. In a machine for testing threads the combination ofi a weight,attached to one end of the thread, suspension means for the other end ofsaid thread, a rotary crank connected to said suspension means, .meansto rotate said crank, and means to prevent the untwisting of saidthread.

4. In a machine for testing threads the combination of a weight attachedto one end of the thread, suspension means for the other end of saidthread, a rotating crank, a-connecting rod connected to said crank atone end and at the other to said suspension means, a guide for saidconnecting rod and means to prevent untwisting of said thread.

5. In amachine'for testing threads the combination of a weight attachedto one end of the thread, suspension means for the other end of saidthread, a rotating crank, a connecting rod connected to said crank atone end and at the other to said suspension means, means forming a slideway to guide said connecting rod, means to prevent untwisting of saidthread, and

means to sto said rotating crank automatically on the reakage of athread.

6. In a machine for testing threads the combination of suspension meansfor said thread a rotating crank, a rod connecting said crank to saidsuspension means, a guide for said latter end of said rod in order togive reciprocating motion to said suspension means, a weight, bifilarconnections between said weight and the end of said thread remote fromsaid suspension means, and means to retain said bifilar connections inthe same relative positions in order to prevent untwisting of' thethread.

7. In a machine for testing threads the combination of suspension meansfor said thread a rotating crank, a rod connecting said crank to saidsuspension means, a guide for said latter end of said rod, a weight,bifilar connections between said weight and theend of said thread remotefrom said suspension means, and a stationary sleeve encircling eachelement of said bifilar connection.

8.. In a machine for testing threads the combination of suspension meansfor said thread a rotatin crank, a rod connecting said crank to saisuspension means, a guide for said latter end of said rod, a weight,bifilar connections between said weight and vthe end of said threadremote from said suspension means, a stationary sleeve encircling eachelement of said bifilar connection, and an electric cut out arrangedbeneath said weight and ada ted to stop the rotation of said crank on te falling of said weight through the breakage of said thread.

9. In a. machine for testing threads the combination of suspension meansfor said threads a rotating crank means to give said crank non-uniformangular motion a rod connecting said crank to said suspension means, aguide for said latter end of said rod in order to give reciprocatingmotion to said suspension means, a weight, bifilar connections betweensaid weight and the end of said thread remote from said suspension meansand means to retain said bifilar connections in the same relativepositions in order to prevent untwisting of the thread.

In witness whereof, I have hereunto signed my name this 28 day ofJanuary 1924, in the presence of two subscribin witnesses.

ARTHUR ERNEST XLEY.

Witnesses:

' JOHN WILLIAMSON,

WILLIAM LENNON.

